Also
# You go bald every time you do your homework.
# You're constantly reminded of how little you know.
# You will never think the same of a toy magnet ever again.
# You can't sit through an X-ray without picturing how the actual X-ray photons are generated and what exactly they're doing to you at the moment.
# You're met with wide eyes and slack jaws when you tell people what classes you're taking that semester.
# You can pick out the scientific flaws in Star Trek episodes.
# New people always ask you what you want to do when you get out of college...and you're like..."If I get out..."
# You can stumble your way through Greek writing, having taken absolutely no Greek language classes before.
# Your homework looks like it's written in an alien language.